1. Field of the Invention
The present invention relates to a lens-fitted photographic film unit having a photograph-taking function, more particularly to a lens-fitted film unit of which an incorporated component is easily removed at the time of disassembly.
2. Description of Related Art
Lens-fitted photographic film units are sold at a low cost, comparable to a conventional film, and are available wherever ordinary photographic films are sold. It is easy to buy a lens-fitted photographic film unit and to take photographs without a camera, if one has brought no camera along but wants to take photographs. Such a film unit is illustrated in FIG. 9 and has a main body 13 which is attached to a front cover 15 and a rear cover 16, in which a taking lens 5, a film advancing knob 9 of a film wind-up mechanism and a shutter mechanism 12 are incorporated, and which contains in a light-tight fashion a 135-type photographic film in a cassette as defined by ISO code 1007, 1979 version. The two covers 15 and 16 are provided with claws 23 and holes 25 which are coupled respectively with holes 21 and claws 19. The detention of the claws 19 and 23 in the holes 21 and 25 prevents the main body 13 from being detached from the main body 13.
The main body 13 is provided with a film supplying chamber 28 and a film take-up chamber 29 formed on opposite lateral sides of the taking lens 5. An unexposed film 30 is wound in a roll and contained in the film supplying chamber 28. A user who has purchased the film unit winds up the film 30 frame by frame at each exposure on a spool 31 in a cassette body 32 loaded in the film take-up chamber 29, and forwards the film unit in its entirety to a photo laboratory when the whole strip of the film is exposed. An operator at the laboratory unloads the cassette body 32 containing the exposed film 30 from the film unit and subjects it to development and printing in accordance with conventional photographic processing techniques.
The user receives photoprints and a negative film but does not receive the film housing of the film unit. The film housing after processing has heretofore been destroyed and discarded as a waste product. However, problems arise from the increase in waste products and the destruction of the environment caused thereby, so that it is desirable to be able to reuse the film housing after processing.
But the known front and rear covers 15 and 16 have a construction inappropriate for reuse because they can accumulate deposits of dirt during the use of the film unit. Moreover, the claws and holes are fragile and can be damaged when disassembling the film housing. On the other hand, the main body 13 is usually free from dirt deposits or damage because it is protected by the two covers 15 and 16. It would therefore be highly advantageous, if possible, to save and reuse the main body 13 with the taking lens 5, the film wind-up mechanism and the shutter mechanism 12.
There are also lens-fitted photographic film units with an electronic flash device incorporated therein. The electronic flash device is also produced at a low cost in order to keep the film units inexpensive. Its construction is improved for this purpose by supporting a light emitting section directly on a printed-circuit board constituting an electronic flash circuit, and by soldering an X contact or synchro switch to the printed-circuit board, which X contact actuates the electronic flash device to flash in synchronism with the time of full opening of a shutter blade mounted on the film housing. Although such electronic flash devices have heretofore been discarded along with the film housing after processing in the laboratory, it is also desirable to reuse the flash unit.
As indicated above, the claws 19 and the holes 21 of the main body 13 attached to the front and rear covers 15 and 16 can be damaged in disassembly, e.g. by use of a jig. Such a damaged main body 13 will be only loosely attached to newly provided front and rear covers, and there can be difficulty in assembling a new film unit because of deformation of the claws 19 and the holes 21.
In the electronic flash device assembled by use of soldering, there is a problem of liability of incomplete flashing caused by an incomplete soldering of the X contact to the printed circuit board. Prevention of the incomplete emission necessitates a secure fixation by applying excess solder. However, an excessively secure fixation of the X contact on the printed circuit board requires considerable labor in removing the electronic flash device from the film housing for the purpose of reusing the electronic flash device.